Today, the increasing functional demands placed on a toothbrush head often make it necessary to provide head geometries which, owing to their complex inner structure, are difficult to produce by injection molding. During the injection molding process the plastic material flowing into the die for molding the head is exposed to turbulence between the various tufting holes and other recesses or cavities of the molding and therefore flows very unevenly, particularly to undercuts or more complex structures lying farther away from the injection point. This problem is aggravated as soon as plastic materials are used for the head which exhibit greater shrinkage on cooling subsequent to the injection molding process. Depending on the inner structure of the head, visual faults or sunk spots, in particular also on the rear side of the head, are the undesired consequence.
It would be desirable to provide a toothbrush which has a complex inner structure within the head that has a visually pleasing rear side. It would also be desirable to provide a suitable method to make such a toothbrush.
Further advantages and application possibilities of the present invention will become apparent from the subsequent description of embodiments with reference to the accompanying drawing. It will be appreciated that any feature described and/or represented by illustration, when used singularly or in any meaningful combination, forms the subject matter of the present invention, irrespective of their summary in the claims or their back-reference.